My dual trailer has class-c tires that are rated for 90 psi. This seems excessive to me and I am wondering what the rest of you, with class-c tires, actually use for inflation pressure. Thanks.

Fill what is recommended by the rating on the sidewall. Adjust your tongue weight accordingly too as recommended.
Underinflation can give problems, over inflation can give problems.

If you are unsure, call a tire dealer like discount tire.

i.e.) I've seen road bikes that call for 60-80 lbs on bicycle tires.

I have a single trailer with 480-12's and it calls for 60lbs

trailer towing basics

please read the tire safety information below:

Tire Safety

Tire inflation is important !!

The psi that is written on the side of the tire is the max pressure the tire should have while it is cool. When the tire has been driven for a while it warms up. the pressure then increases when it is warm. If your max pressure is 90 psi like you say, I would recommend you pressurize them somewhere between 60-75 psi.

That's good stuff! However, the 90 psi rating on the sidewall refers to "maximum" pressure according to the documentation you provided. I tend to avoid the "maximum" because one relative and one aquaintance both ended up with broken arms and lacerations attempting to always stay at maximum, albeit this was quite some time ago when tire quality wasn't what it is now. Does everyone inflate their tires to the "maximum" pressure recomendation?

GP1200,
Thats where I'm at (65-70 psi). Just wondering if everyone else is doing the same. Thanks.

I think the maximum rating is if you are going to be loading that trailer tire up to it's maximum load limit.

The maximum pressure for the tire is written in small type around the side of the tire, next to the metal wheel rim. It is the PSI (pounds per square inch) number and will read like this "(60 PSI) max pressure". Max pressure means the most air to be put into this tire NEVER exceed this amount. This maximum pressure is used when you are carrying a heavy load, however, this is not the daily standard amount of pressure. The daily usage, standard amount for a tire example, tire size of 65/175 R14 is between 32 - 34 pounds of air. For these size of tires and the 15's, this standard pressure is used.

To get correct PSI readings always check the air pressure before you drive your vehicle or tow a trailer while the tire is cold. Why? because of heat and expansion. Heat/Expansion will increase the gauge reading by 3 - 5 pounds.

This message has been edited. Last edited by: RX951,

I never run the max pressure on my tires. There really is no need to put that much strain on the seals. If you have to haul so much weight that you are pushing the weight limits of the trailer, then it is time to get a bigger trailer. Besides, running a lower pressure allows the tires to "give" a little. This lets the trailer ride better since it has a little softer suspension.